Method for reconditioning hot oil pump blocks



C. C. BEAL July 14, 1942.

Filed Nov. 21, 1939 METHOD FOR RECONDITIONING HOT OIL PUMP BLOCKS Fla-3C. CiqBl-ZAL 1 v R- ,SW BY aim SK /m HIS ATTORNEYS TOR Patented July 14,1942 METHOD FOR RECONDITIGNING HOT OIL PUMP BLOCKS Charles C. Beal, PortArthur, Tex., assignor, by mesne assignments, to The Texas Company, NewYork, N. Y., a corporation of Delaware Application November 21, 1939,Serial No. 305,465

1 Claim.

This invention relates to a method for reconditioning or reclaimingcondemned liquid ends or blocks of hot oil pumps.

In oil refineries and other places where oils are treated and handled itis frequently necessary to transport such oils from one point toanother, and the usual practice is to convey the oils through pipe linesby means of pumps. When it becomes necessary to convey the oils while ina heated condition, pumps of a special design are ordinarily employed.These special pumps are what are commonly referred to as hot oil pumps,and they are designed to withstand the high temperatures, and frequentlyhigh pressures, of the oils handled by them. However, after long andgenerally continuous operation these hot oil pumps are aifected by thecorrosive action of the heated oils and the walls of the variousopenings and ports become so badly corroded that the efficient operationof the pumps is impaired, corrosion taking place particularly betweenthe valve ports and in the suction and discharge channels. When thiscondition occurs, the usual refinery practice is to discard the damagedpump blocks and replace them with new blocks, but obviously this is acostly procedure.

It is an object of the present invention to provide a method forreconditioning or reclaiming the blocks of hot oil pumps which have beenrendered useless or practically so by the corrosive action of the hotoils handled by them. More specifically, it is an object of thisinvention to provide a method for reconditioning the various openingsand ports of badly worn hot oil pump blocks to restore them to theiroriginal state of efliciency. Still more specifically, the invention hasfor an object to provide a method for removing the corroded and pittedmetal from the walls of the openings and ports of hot oil pump blocks,and then lining the various openings with a corrosion resistant metaland machining the lined ports and passageways to restore them to theiroriginal sizes.

Additional objects, features and advantages of the present inventionwill appear from the folchined to size and with a lining of corrosionresistant metal.

In Fig. 1 of the drawing there is shown a typical hot oil pump block I,preferably-formed I I2 and II, respectively, is interconnected withcross ports I6 of various sizes, while a plurality of valve ports l8rise vertically to the upper surface of the block to. Small holes orconduits 20, 20, each communicating at one end with the lower openingl2, are drilled through the botlowing description when taken inconnection 5 of Fig. 1 showing the openings and ports of the blockmachined to over-size and completely filled with corrosion resistantmetal; and

Fig. 3 is a sectional view taken on the line 3-3 tom of the block l0near the opposite ends thereof.

The preparation of a block such as that described above forreconditioning includes the sand blasting and cleaning of all surfaceswhich are to be lined, and all the openings and ports which are to bereconditioned are over-size ma.- chined in order to assure minimum linerthickness. After the machining of the openings and ports to over-sizehas been completed, it is generally desirable to core (not shown) theseopenings with extra heavy pipe tofacilitate machining and save metal.The coring may be accomplished in any suitable manner.

Prior to pouring the corrosion resistant metal, which is preferably analloy steel containing as alloying constituents 4-6% chromium and 50%molybdenum, the entire block is heated to a temperature of approximately1300 F. The block may be rammed up with sand to hold the temperature andinsure safety until it is ready for pouring. The molten metal, whenready for pouring, has a temperature of approximately 2900 F. and thepouring is done before the block loses its red heat. The center orlargest vertical opening [8, which is connected to all ports,

may be conveniently used as a pour basin, as

through it access can be had most easily to all of the other openingsand ports.

After all of the openings and ports have been completely filled with thecorrosion resistant metal the block is allowed to cool, after which allexcess metal is burned off and the entire block is then annealed in anannealing oven and upon completion of the annealing operation the cyl- 5inder or block is completely machined, the various ports and openingsbeing bored to the desired size. The outer contacts of the chromiumsteel to the carbon steel block, and any defects found upon machining,are welded, after which of Fig. 1 showing the openings and ports matheentire block is re-annealed. After the foundry and machine work isotherwise completed the block I! may be turned upside down and ironcement poured into one of the holes 20. The cement is allowed to fill upany of the voids then remaining in the block due to shrinkage. Pouringof the iron cement is preferably continued until it has filled all ofthe voids and begins to run out the opposite end of the .block. As aresult of the reconditioning of hot oil pump blocks in the manrer hereindescribed the reclaimed blocks are again ready for service, andexperience to date indicates that blocks reclaimed in this manner willhave a life exceeding that of the original factory blocks of forgedsteel.

As illustrative of one corrosion resistant metal which has been found tobe satisfactory for reconditioning pump blocks in the manner hereindescribed, a typical analysis range is given below:

Carbon 0.15-0.20 Silicon 0.30-0.45 Manganese 0.40-0.60 Chromium4.00-6.00 Molybdenum 0.50-0.60

It will be readily appreciated from the foregoing that while theinvention has been described as applicable particularly to thereconditioning or reclaiming of a particular type of hot oil pump block,it is equally applicable to the reconditioning or reclaiming of othertypes of hot oil pump blocks or various types of equipment, such aspumps, motor cylinder blocks and the like.

Obviously many modifications and variations of the invention, ashereinbefore set forth, may be made without departing from the spiritand scope thereof, and therefore only such limitations should be imposedas are indicated in the appended claim.

I claim:

The method of reconditioning a worn hot oil pump block having openingsand ports therein, which comprises machining said openings and ports toover-size, filling said openings and ports with molten corrosionresistant metal to form a substantially solid block, rough machining newopenings and ports through the corrosion resistant metal, welding themetals at all surface points, annealing the .block for stress relief,and machine finishing the openings and ports to substantially theoriginal sizes.

CHARLES C. BEAL.

